Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 19 Jan 2015

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

8(5)

29(29)

27(-)

40(17)

0.3(3)

12(51)

South

9(6)

36(36)

7(-)

45(19)

0.4(4)

15(55)

East

6(4)

29(29)

9(-)

60(25)

0.4(4)

17(57)

West

2(1)

34(34)

9(-)

60(25)

0.4(4)

16(56)

Central

6(4)

32(32)

17(-)

59(25)

0.3(3)

11(47)

1-hr PM2.5 (µg/m3)b Readings on 19 Jan 2015

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

12

11

9

10

9

16

13

11

13

15

17

16

South

12

7

13

12

10

6

11

14

13

26

29

28

East

15

13

15

18

23

22

14

20

15

20

19

22

West

14

15

16

16

14

14

15

19

10

22

20

23

Central

10

8

13

9

6

11

14

12

13

6

10

13

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

12

15

14

14

15

10

13

15

9

9

11

-

South

31

28

28

27

22

11

7

5

16

5

3

-

East

19

22

19

18

19

19

17

11

13

12

14

-

West

22

20

21

19

18

20

21

15

12

9

12

-

Central

18

17

6

16

11

14

14

16

10

7

11

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
19 Jan 2015

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

48

46

51

51

52

52

52

53

53

55

56

59

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

60

60

59

59

57

56

55

53

52

45

42

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.